Answer:
a karyotype
Explanation:
A karyotype allows you to see and count a organism's chromosomes to make sure there are no abnormalities.
Answer:
e. Purines pair with pyrimidines
Explanation:
Diameter of DNA double helix is uniform through out the structure and it is 2 nm. This uniformity is due to the base pairing between a purine and a pyramidine. Purine base is made of two rings and pyramidine base has a single ring. All the bases are either derived from purine or from pyramidine structure and a purine always pairs with pyramidine. Two purines or two pyramidines can not pair with each other. So at any point along the DNA molecule, the sugar phosphate backbones always have three ring structure between them, hence the uniform diameter.
Sprial, elliptical and irregular...
Answer:b-cells produce antibodies or (memory b-cells)
Explanation:B cells are one of the two types of lymphocytes, the other kind being T cells. B-cells have a very specific function: the production of antibodies, which play a major role in immunity. Memory cells remember specific foreign invaders, pathogens, and antigens to fight them off if they come back in the future.
